It was discussed that materialized views can be fast refreshed, but there can still be a lag. Real-time MVs can roll forward information based on the logs, which is like doing a fast refresh, but it is completing it in real time.

Real-time functionality is available if the following is true:

•     QUERY_REWRITE_INTEGRITY is enforced or TRUSTED

•    MV is not set to REFRESH … ON COMMIT

•     MV must be able to do a fast refresh

•     ENABLE ON QUERY COMPUTATION is used

Now when the MV is queried, the data will wind forward of a stale state making the data appear fresh to the statement. The changes are not persisted in the MV does a refresh.

Oracle Views

This chapter covered the database objects and views. However, these were very different views. A view gives you a way to logically present data to an application, reporting,

or other database and data management tools. So, even though views, JSON duality views, and materialized views provide different functionality and have different purposes, they expose data stored in relational tables. JSON duality gives you the data as JSON documents that are generated on demand and organized both relationally and hierarchically.

Materialized views store the snapshot of the data and provide better performance and can be used to perform analytical queries to also store.

The simplicity of using native database commands to create various views and set up access to these views through normal database security is a great tool to provide the needed data for applications and APIs.

Now with Oracle 23c having JSON-relational duality views provides standardized, straightforward joins with all sorts of data including JSON to state-of-the art analytics, machine learning, and reporting.